Design & Engineering · Hydrofoil

How a hydrofoil works, and how we design it.

A hydrofoil is a submerged wing that lifts the hull out of the water: less drag, more speed, more efficiency. We design hydrofoil systems from concept to validation, combining fluid-dynamic design, calculation, CFD simulation, prototyping and testing.

The principle

How a hydrofoil works

As speed increases, the water flowing over the foil profile generates hydrodynamic lift. When lift equals the boat's weight, the hull rises and foiling begins: the wetted surface collapses, drag drops with it, and the boat gains speed and efficiency for the same power.

Its behaviour depends on a few key parameters — foil profile, angle of attack, area and trim — and on phenomena to control such as cavitation, ventilation and stability. This is where rigorous design matters.

  • Lift that raises the hull (foiling)
  • Reduced drag, greater efficiency
  • A more stable, comfortable ride
Cross-section of a hydrofoil profile with flow lines and lift vector

Sizing & calculation

From hydrodynamic calculation to CFD simulation

Foil lift is estimated with L = ½ · ρ · v² · A · CL: ρ is water density, v is speed, A is the foil area and CL is the lift coefficient of the profile. It is the starting point to size profile, area and angle; the design is then refined with hydrodynamic design software and CFD simulations.

Preliminary calculation

Estimating lift, drag and foil area as a function of speed and load, to define the foil's starting configuration.

CFD simulation

Modelling flow, pressure, cavitation and drag in real conditions, to verify and optimise the profile before building it.

Structural check (FEM)

FEM analysis of loads and materials (often carbon composites) to ensure the stiffness, strength and safety of the system.

Ride optimization

Optimising ride and trim

A well-designed foil must then be optimised in real use: flight height, flight angle, stability and control change with speed and sea state. We work on geometry, load distribution and settings to achieve stable, efficient flight across the whole operating envelope.

  • Optimal flight height and angle
  • Stability and control in every condition
  • Validation with CFD, prototyping and on-water testing
A boat foiling, lifted above the water by a hydrofoil

What we design

Hydrofoil systems, from concept to validation

Integrated functional, structural and fluid-dynamic design, for recreational boating, yachts and water-sports equipment.

01

Functional design

Defining mission, target performance and foil-system architecture based on the boat and its use.

02

Fluid-dynamic design

Profile selection and optimisation, hydrodynamic calculation and CFD simulations for lift, drag and cavitation control.

03

Structural design

Sizing and FEM verification of foils and fittings, with composite materials and materials characterisation.

04

Prototyping

Building prototypes and components, including additive manufacturing, to move from model to real part.

05

Testing & validation

Virtual and physical tests, on-water testing and trim tuning (ride optimization) through to validation.

06

Continuous optimisation

Test-data analysis and design iterations to improve stability, efficiency and ride comfort.

All design services

Frequently asked questions

Hydrofoils: answers in brief

How does a hydrofoil work?
A hydrofoil is a submerged wing attached to the hull. As speed increases, the water flowing over the foil profile generates hydrodynamic lift: when lift equals the weight, the hull rises out of the water (foiling). With the wetted surface reduced, drag drops sharply, speed and efficiency increase and the ride becomes more stable.
How is a hydrofoil sized? Do you need software or a calculator?
Foil lift is estimated with L = ½ · ρ · v² · A · CL, where ρ is water density, v is speed, A is the foil area and CL is the lift coefficient of the profile. This is the starting point to size profile, area and angle of attack; the design is then refined with hydrodynamic design software and CFD simulations that model flow, cavitation and drag in real conditions.
What is hydrofoil ride optimization?
It is the optimization of ride and trim: flight height, flight angle, stability and control across different speed and sea conditions. We work on foil geometry, load distribution and settings, validating with CFD simulation, prototyping and on-water testing for optimal lift, control and efficiency.
What materials are hydrofoils made of?
Typically carbon-fibre composites for their high stiffness-to-weight ratio, plus metal alloys where needed. Alongside design, we provide materials characterisation with destructive and non-destructive testing to ensure strength, durability and safety.

A hydrofoil project on the horizon?

Let's design your hydrofoil system

From hydrodynamic calculation to validation: tell us the boat and the goal, and we'll define the technical path together.

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